diff options
| author | Helge Deller <deller@gmx.de> | 2023-05-22 15:11:16 +0200 |
|---|---|---|
| committer | Helge Deller <deller@gmx.de> | 2023-05-24 14:23:07 +0200 |
| commit | 15e64ef6520ea8702998db05b87fa5c3d3d40710 (patch) | |
| tree | b7f67430b55167a2aeae50fd95fd4d4c50e2d2f8 /arch/parisc/kernel/traps.c | |
| parent | b6405f0829d7b1dd926ba3ca5f691cab835abfaa (diff) | |
parisc: Add lightweight spinlock checks
Add a lightweight spinlock check which uses only two instructions
per spinlock call. It detects if a spinlock has been trashed by
some memory corruption and then halts the kernel. It will not detect
uninitialized spinlocks, for which CONFIG_DEBUG_SPINLOCK needs to
be enabled.
This lightweight spinlock check shouldn't influence runtime, so it's
safe to enable it by default.
The __ARCH_SPIN_LOCK_UNLOCKED_VAL constant has been choosen small enough
to be able to be loaded by one LDI assembler statement.
Signed-off-by: Helge Deller <deller@gmx.de>
Diffstat (limited to 'arch/parisc/kernel/traps.c')
| -rw-r--r-- | arch/parisc/kernel/traps.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c index f9696fbf646c..13df6169f9e2 100644 --- a/arch/parisc/kernel/traps.c +++ b/arch/parisc/kernel/traps.c @@ -47,6 +47,10 @@ #include <linux/kgdb.h> #include <linux/kprobes.h> +#if defined(CONFIG_LIGHTWEIGHT_SPINLOCK_CHECK) +#include <asm/spinlock.h> +#endif + #include "../math-emu/math-emu.h" /* for handle_fpe() */ static void parisc_show_stack(struct task_struct *task, @@ -309,6 +313,12 @@ static void handle_break(struct pt_regs *regs) } #endif +#ifdef CONFIG_LIGHTWEIGHT_SPINLOCK_CHECK + if ((iir == SPINLOCK_BREAK_INSN) && !user_mode(regs)) { + die_if_kernel("Spinlock was trashed", regs, 1); + } +#endif + if (unlikely(iir != GDB_BREAK_INSN)) parisc_printk_ratelimited(0, regs, KERN_DEBUG "break %d,%d: pid=%d command='%s'\n", |